Compressed gas storage means, more especially for the inflation of a gas bag for a vehicle occupant restraining system, are opened in a crash by activation of small pyrotechnic charge so that the gas stored in the storage container may escape and cause deployment of the gas bag. In this respect the gas bag must completely deploy within an extremely short period of time, a high gas pressure being required for rapid filling of the gas bag and such gas pressure must be maintained in the final phase of deployment as well. A gas pressure which is only high at the outset on the contrary tends to be an obstacle for the initial part of deployment and is unable to ensure full deployment of the gas bag.